WorksheetsHalf-Life Practice
Total questions: 17
Worksheet time: 2hrs 13mins
Name
Class
Date
1.
If 10 mg of iodine 131 is given to a patient, how much is left after 24 days? The half-life of iodine-131 is 8 days.
a)
1.25mg
b)
0.25mg
c)
5 mg
d)
10mg
2.
The half-life of strontium-90 is 25 years. How much strontium-90 will remain after 100 years if the initial amount is 4.0 g?
a)
2.0g
b)
0.25g
c)
1g
d)
2.5g
3.
You have 100 grams of radioactive C-14.
How many grams are left after 1 half life?
a)
100 grams
b)
25 grams
c)
2 grams
d)
50 grams
4.
What is Half-life?
a)
The amount of time it takes for some of the nuclei in a sample of the isotope to decay
b)
The amount of time it takes for half the electrons in a sample of the isotope to decay
c)
The amount of time it takes for half the nuclei in a sample of the isotope to decay
d)
the amount of time it takes to double the nuclei in a sample of the isotope to decay
5.
When nuclei decay, massive amounts of __________ is released.
a)
energy
b)
jello
c)
protons
d)
neutrons
6.
What is the half-life of iodine-131?
a)
32 days
b)
8 days
c)
16 days
d)
24 days
7.
What is the Half life of this isotope?
a)
5 seconds
b)
10 seconds
c)
15 seconds
d)
20 seconds
8.
What is the Half Life of this isotope?
a)
3 days
b)
5 days
c)
8 days
d)
10 days
9.
What is the half-life of iodine-131?
a)
32 days
b)
8 days
c)
16 days
d)
24 days
10.
The half-life of Zn-71 is 2.4 minutes. If one had 100.0 g at the beginning, how many grams would be left after 7.2 minutes has elapsed?
a)
100.0g
b)
50.0g
c)
12.5g
d)
8.5g
11.
Fermium-253 has a half-life of 0.334 seconds. A radioactive sample is considered to be completely decayed after 10 half-lives. How much time will elapse for this sample to be considered gone?
a)
0.334 seconds
b)
3.34 seconds
c)
1.77 seconds
d)
13.4 seconds
12.
Barium-122 has a half-life of 2 minutes. A fresh sample weighing 80 g was obtained. If it takes 10 minutes to set up an experiment using barium-122, how much barium-122 will be left when the experiment begins?
a)
0.25g
b)
2.5g
c)
25g
d)
80g
13.
If the half-life of uranium-232 is 70 years, how many half-lives will it take for 10 g of it to be reduced to 1.25 g?
a)
1 half-life
b)
2 half-lives
c)
3 half-lives
d)
4 half-lives
14.
Which diagram best represents the percentage of this radioactive isotope sample that will remain after 2 half-lives?
a)
b)
c)
d)
15.
After 22,800 years, approximately what percentage of the original carbon-14 remains?
a)
15%
b)
12.5%
c)
6.25%
d)
3.125%
16.
If one-fourth of the carbon-14 is remaining then how many half-lives have passed?
a)
1
b)
2
c)
3
d)
4
17.
Selenium-83 has a half life of 25 minutes. How many minutes would it take for a 20 milligram sample to decay and only have 1.25 milligrams of it remaining?
a)
25 minutes
b)
50 minutes
c)
75 minutes
d)
100 minutes
100 %
